Rivermatics

USGS Streamgage 11289651

Combined Flow Tuolumne River + Modesto Cn + Turlock Cn

Combined Flow Tuolumne River + Modesto Cn + Turlock Cn is USGS streamgage 11289651 in California, monitoring river discharge in hydrologic subbasin 18040009. It drains a watershed of about 1,538 square miles. Discharge records at this site go back to 2025. Typical flow runs near 2,877.1 cfs in July and 2,480 cfs in April, with the higher of the two arriving in July. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.

View live conditions & forecast →

Gauge details

State
California
Drainage area
1,538 sq mi
Subbasin (HUC-8)
18040009
Coordinates
37.66632, -120.44214
USGS site number
11289651
Records begin
2025-11-25 (1 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Combined Flow Tuolumne River + Modesto Cn + Turlock Cn. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
1,367 1,557 1,726
1,278 1,543 1,815
1,155 1,477 1,778
1,028 1,433 1,783
1,008 1,427 1,811
901 1,398 1,822
846 1,389 1,845
900 1,406 1,849
899 1,422 1,895
803 1,375 1,846
683 1,315 1,802
743 1,348 1,833
571 1,214 1,736
543 1,236 1,776

All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.

Typical flow by month

Long-term daily discharge percentiles from the USGS record (up to 55 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 162.7 487.3 4,382.9
February 161.9 739.6 5,417.2
March 318.1 1,794.5 6,838.4
April 940.3 2,480 8,637.7
May 1,112.2 2,573.9 8,687.1
June 1,442.6 2,551.3 6,760
July 1,787 2,877.1 4,488.7
August 1,443.5 2,500.6 3,768.7
September 551.4 1,553.7 3,025.7
October 238.2 1,092.1 2,486.1
November 166.9 415.7 1,668.4
December 165.5 373.7 2,792.9

All values in cubic feet per second (cfs).

Common questions

When does Combined Flow Tuolumne River + Modesto Cn + Turlock Cn normally run highest?
July, on the long-term record. The median daily flow that month is about 2,877.1 cfs, against 373.7 cfs in December, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Combined Flow Tuolumne River + Modesto Cn + Turlock Cn?
It depends on the month. In January, half of days historically fall near 487.3 cfs, with the middle 80% of days between 162.7 and 4,382.9 cfs. The month-by-month table on this page gives the full range.
How long has Combined Flow Tuolumne River + Modesto Cn + Turlock Cn been measured?
Discharge records at USGS site 11289651 begin in 2025, about 1 years, covering roughly 9,130 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Combined Flow Tuolumne River + Modesto Cn + Turlock Cn?
Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
Where is Combined Flow Tuolumne River + Modesto Cn + Turlock Cn?
The gauge sits at 37.66632, -120.44214, in California, in hydrologic subbasin 18040009, draining roughly 1,538 square miles.
Can I use Combined Flow Tuolumne River + Modesto Cn + Turlock Cn data for flood or safety decisions?
No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.

Other gauges in this subbasin